While the modification of substrates using chemical structures has been widely employed, many conventional substrate modifiers have limited utility. One example is the modification of gold surfaces with thiols to form monolayers. The relatively weak binding energy, ill-defined binding geometry, and non-conductive nature of S—Au bonds limits the applications of gold surfaces modified with thiols. For example, the relatively weak S—Au bond (˜45 kcal/mol) can lead to monolayer desorption at moderate temperatures (˜100-150° C.). In addition, the S—Au bonds are typically non-conductive, which can limit their use in molecular electronics applications. The association of persistent carbenes with substrates has received little attention.
Accordingly, improved compositions, articles, and methods are needed.